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Delayed timing of heart and arterial sounds in patients with implanted pacemakers
Insights
Pacemaker implantation significantly prolongs the timing of heart sounds (S1, S2) and arterial sounds (Korotkoff sounds) relative to the cardiac cycle. This study quantifies these timing changes in patients with pacemakers.
Area of Science:
- Cardiology
- Biomedical Engineering
- Medical Device Technology
Background:
- Pacemaker implantation is a common intervention for cardiac rhythm disorders.
- Understanding the hemodynamic effects of pacemakers is crucial for optimizing patient outcomes.
- The timing of cardiovascular events can be altered by artificial pacing.
Purpose of the Study:
- To investigate the impact of pacemaker implantation on the timing of heart sounds and arterial sounds.
- To quantify the changes in intervals between the QRS complex and various cardiovascular events post-pacemaker implantation.
Main Methods:
- Recorded timing of heart sounds (S1, S2) and arterial sounds (Korotkoff) relative to the QRS complex onset.
- Studied patients before and after pacemaker implantation, and after implantation only.
- Utilized non-invasive methods to measure arterial pressure changes.
Main Results:
- Marked prolongation of the QRS-to-diastolic Korotkoff sound interval (QKd) from 206 to 294 msec.
- Significant prolongation of the QRS-to-systolic Korotkoff sound interval (QKs) from 329 to 414 msec.
- Increased intervals between QRS and S1 (approx. 90 msec) and QRS and S2 (approx. 70 msec), alongside changes in heart rate and blood pressure.
Conclusions:
- Pacemaker implantation leads to significant delays in the timing of both heart and arterial sounds relative to the cardiac electrical cycle.
- These timing alterations may have implications for cardiovascular hemodynamics and require further investigation.
- Non-invasive monitoring provides valuable insights into pacemaker-induced cardiovascular timing changes.
Abstract:
We have recorded the timing of the heart sounds and the arterial sounds with reference to the onset of each cardiac cycle in 16 patients before and after implantation of a pacemaker prosthesis, and in an additional 18 patients after pacemaker implantation only. The interval between the QRS complex and the Korotkoff sound at diastolic pressure (QKd) is markedly prolonged, from 206 to 294 msec., a change corresponding to 10 standard errors of the mean difference. Likewise, the Q-Korotkoff interval at systolic pressure (QKs) is prolonged from 329 to 414 msec. The interval between the QRS complex and the onset of the first sound (S1) is prolonged by approximately 90 msec., whereas the interval between the QRS and the second heart sound (S2) is prolonged by 70 msec. We noted an associated increase in heart rate, a slight decrease in systolic pressure, an increase in diastolic pressure, a decrease in pulse pressure, and a slight decrease in the deltaP/deltat at the brachial artery measured indirectly and noninvasively.